The helicity amplitudes A$_{1/2}$ and A$_{3/2}$ for the D$_{13}(1520)$ resonance obtained from the $\vec{\gamma} \vec{p} \to p \pi^0$ reaction}

TL;DR

This study measures the helicity dependence of the gamma-proton to proton-pi-zero reaction in the 550-790 MeV range, providing new insights into the D13(1520) resonance parameters using polarized beams and targets.

Contribution

First measurement of helicity dependence for this reaction in the specified energy range, enabling extraction of D13(1520) resonance parameters.

Findings

Helicity dependence measured for the first time in this energy range.

Data predominantly sensitive to the D13(1520) resonance.

Parameters of the D13(1520) resonance determined from the data.

Abstract

The helicity dependence of the $\vec{\gamma} \vec{p} \to p \pi^0$ reaction has been measured for the first time in the photon energy range from 550 to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4$\pi$-detector system, a circularly polarized, tagged photon beam, and a longitudinally polarized frozen-spin target. These data are predominantly sensitive to the $D_{13}(1520)$ resonance and are used to determine its parameters.